1. Field of the Invention
The present invention relates to a winding roll lifting device, or simply a lifting device. The winding roll carries sheet materials, such as synthetic resin film, paper, film laminate paper and the like, that are wound around its winding shaft, and the lifting device may be operated so that it can move the winding roll that is initially placed in its vertical or horizontal position toward its horizontal position or vertical position. The present invention also relates to a winding roll holding device, or simply a holding device, that may be used in conjunction with the lifting device, wherein in a situation in which the winding roll being lifted by the lifting device, with its chuck member being inserted into a central recess provided on the winding roll, is slipping out of the lifting device, the holding device may be operated automatically so that it can engage the inner wall of the central recess on the winding roll more firmly.
2. Prior Art
Conventionally, a plurality of parallel winding rolls (e.g. four to five winding rolls), each of which carries sheet materials, such as synthetic resin film, paper, film laminate paper and the like, that are wound around its winding shaft, are placed in their vertical positions onto a transport pallet. Those winding rolls may be traveling on the transport pallet toward the workstation, where the winding rolls are repositioned from the vertical state to the horizontal state, and are then mounted on a machine. In this prior art, the primary considerations are to assure the quality of the sheet materials carried by the winding rolls and to utilize the available space effectively.
Generally, the winding roll lifting device that is used in moving the winding roll from its vertical position into its horizontal position has a chuck member that may engage a central recess provided on the winding roll by being inserted into the central recess, when it is initially placed in its vertical position. Actually, when the winding roll is to be moved from its vertical position to its horizontal position, the chuck member may be inserted into or engage the central recess from the top, and may then be turned pivotally into its horizontal position, causing the winding roll to be raised into its horizontal position.
In the conventional winding roll lifting device described above, the part of the lifting device that dynamically acts as a point of force (which usually corresponds to the hook member in the lifting device) is initially located just above the center of gravity of the winding roll, and is aligned with the center of gravity along the vertical line. As the winding roll is being lifted by the lifting device toward its horizontal position, however, the distance between the position of a vertical line along which the force point is located and the position of a vertical line along which the gravity point of the winding roll is located becomes greater. In general, the location along the vertical line of the hook member of the lifting device acting as the force point is fixed, and the location along the vertical line of the center of gravity of the winding roll may move further away from the location of the force point, as the winding roll is being lifted into its horizontal position. Thus, the prior art lifting device has a problem in that the pivotal movement of the chuck part from its vertical position to its horizontal position cannot occur with stability. The problem that causes the distance between the vertical line position where that part of the lifting device that dynamically acts as the force point (which corresponds to the hook member of the lifting device) is located and the vertical line position where the center of gravity of the winding roll is located to become gradually greater may become more serious when elongated objects, such as winding rolls, that are massive or have a greater width than diameter are being lifted from the vertical position into the horizontal position. This may also cause the instability problem to become worse when such objects are being lifted by the chuck member from the vertical position into the horizontal position.
Because the winding roll that carries sheet materials, such as synthetic resin film, paper, film laminate paper and the like wound around its winding shaft, is massive, the instability problem, coupled with the problem that causes the distance between the vertical line location of the force point (which corresponds to the location of the hook member) and the vertical line location of the center of gravity of the winding roll to become greater, may introduce another problem in that the mounting operation of the winding roll in its horizontal position onto a machine cannot be performed with high safety, and the operation cannot proceed with high speed.
As described, the winding roll may be moved from its vertical position into its horizontal position as it is held by the chuck member. To do this, the chuck member includes an inflatable member around its outer surface into which compressed air may be introduced. After the chuck member is inserted into the central recess of the winding roll, the compressed air may be introduced into the inflatable member, which may enlarge the external diameter of the chuck member so that the chuck member can engage the inner wall of the central recess of the winding roll more firmly.
It should be noted, however, that for the massive winding roll, the frictional force between the chuck member and the inner wall of the central recess may not be able to overcome the weight of the winding roll gradually until the winding roll is finally slipping out of the chuck member, even if a large amount of compressed air is introduced into its inflatable member. This may also cause the instability problem when the winding roll is being lifted.
This instability problem may become more apparent when the winding roll is placed in its vertical position, as the total weight of the winding roll acts in the vertical direction.
In light of the problems associated with the winding roll lifting device of the prior art that occur when the winding roll is lifted from its vertical position into its horizontal position, the present invention proposes to provide a winding roll lifting device, or simply a lifting device, that allows the winding roll in its vertical position to be lifted into its horizontal position with high safety and with high speed. The present invention also proposes to provide a winding roll holding device, or simply a holding device, that prevents the winding roll from slipping out of the chuck member while it is being lifted by the chuck member. This holding device may be used in conjunction with the lifting device of the present invention or the lifting device of the prior art described above.
The present invention addresses the problems described above, and solves the problems by allowing the vertical line position of that part of the winding roll lifting device that dynamically acts as a point of force (which usually corresponds to the hook member in the lifting device) to move in the same direction as the direction in which the vertical line position where the center of gravity of the winding roll is located is moving, thereby keeping the distance between the vertical line position of the force point and the vertical line position of the center of gravity as small as possible when the winding roll is being lifted by the lifting device from its vertical position into its horizontal position.
The problems may also be solved by providing a winding roll holding device, or simply a holding device, that includes an eccentric cam member. If a situation where the winding roll being lifted by the lifting device with its chuck member being inserted into the central recess on the winding roll is slipping out of the chuck member should occur, the holding device may be operated automatically so that its eccentric cam member may be forced against the inner wall of the central recess, thereby engaging the inner wall of the central recess of winding roll more firmly.
More specifically, those problems are solved by providing a winding roll lifting device, or simply a lifting device, that includes a main body, the main body including a drive mechanism attached thereto that may be activated to move the winding roll from its vertical position into its horizontal position, a supporting arm member having its base end pivotally mounted to the upper end side of the main body and having its forward end pivotally mounted to that part of the lifting device that acts as the point of force (which corresponds to the hook member of the lifting device), and a chuck member having its base end pivotally mounted to the lower end side of the main body. When the chuck member is driven by the drive mechanism attached to the main body so that it may turn pivotally about the lower end side of the main body, moving from the vertical position into the horizontal position, the supporting arm member may be synchronized with the pivotal movement of the chuck member, turning pivotally about the upper end side of the main body in the direction approaching the chuck member, thereby keeping the distance between the vertical line position of the before described force point (that is, the hook member of the lifting device) and the vertical line position of the center of gravity of the winding roll is maintained as small as possible.
Similarly, the problems are solved by providing a winding roll holding device, or simply a holding device, that may be used in conjunction with the winding roll lifting device of the present invention or the winding lifting device of the prior art. The holding device includes a shaft that is mounted to the forward end of the chuck member of the winding lifting device so that it can advance or retract in the axial direction of the chuck member as it is inserted into the central recess of the winding roll, and an eccentric cam member that is supported on the forward end side of the chuck member and is operatively linked with the advancing or retracting movement of the shaft, so that it can turn pivotally in the axial direction of the chuck member with the advancing or retracting movement of the shaft. Thus, the eccentric cam member may initially be forced against the inner wall of the central recess after the chuck member is inserted into the central recess of the winding roll. If the winding roll should then begin slipping out of the chuck member, the eccentric cam member may be further forced by that slipping action against the inner wall of the central recess, so that the eccentric cam member can engage the inner wall of the central recess on the winding roll more firmly.
More specifically, several aspects of the present invention will be described by referring to the accompanying drawings. In the following description and for the simplicity of the description, the winding roll lifting device may be referred to simply as the lifting device, which should still be understood to mean the winding roll lifting device. In one aspect, the lifting device, which is generally represented by 1, includes a main body 2. The main body 2 includes a drive mechanism (not shown) attached thereto that may be activated to lift a winding roll 30 from its vertical position into its horizontal position. The lifting device also includes a supporting arm member 5 having its base end pivotally mounted to the upper end of the main body 2, a hook member extending from the supporting arm member 5 and pivotally connected to the forward end of the supporting arm member 5, and a chuck member 8b having its base end pivotally mounted to the lower end of the main body 2 and which is adapted to be inserted into a central recess of the winding roll 30. The central recess on the winding roll 30 is configured to accept the chuck member 8a therein. Thus, when the chuck member 8a is driven by the drive mechanism within the main body 2, it can be operated to turn pivotally about the lower end side of the main body 2, moving from its vertical position into its horizontal position. The supporting arm member 5 may then be synchronized with the pivotal movement of the chuck member 8a, turning pivotally about the upper end side of the main body 2 in the direction approaching the chuck member 8a. In this way, the winding roll 30 may be lifted by the chuck member 8a from its vertical position into its horizontal position, with the chuck member 8a being inserted into the central recess of the winding roll 30.
In another aspect, the winding roll lifting device, or simply a lifting device, which is generally represented by 1, includes a main body 2, and the main body 2 includes a drive means 3 attached thereto. The lifting device also includes a supporting arm member 5 having its base end pivotally mounted to the upper end side of the main body 2, a hook member extending from the supporting arm member 5 and pivotally connected to the forward end of the supporting arm member 5, a lifting arm member 7 configured to include the chuck member 8a having its base end pivotally mounted to the lower end of the main body 2 and having its forward end adapted to be inserted into a central recess of the winding roll 30, a supporting shaft member 10 which is driven by the drive means 3 and which moves upwardly and downwardly within the main body, and an arm rod member 11 freely fitted to the supporting shaft member 10 at the middle point thereof and having its first end pivotally mounted to the supporting arm member 5 and having its second end pivotally mounted to the lifting arm member 7.
In still another aspect, the winding roll holding device, or simply a holding device, which is generally represented by 40, may be used in conjunction with the lifting device of the present invention or may be used with the prior art lifting device. The holding device includes a shaft member 38 that may be mounted to the forward end of the chuck member 8a so that the shaft member 38 can advance or retract in the axial direction of the chuck member 8a as the chuck member 8a is inserted into the central recess of the winding roll 30, and includes an eccentric cam member 39 pivotally supported on the forward end of the chuck member 8a and operatively linked with the advancing or retracting movement of the shaft member 38 so that the eccentric cam member 39 can turn pivotally in the axial direction of the chuck member 8a. 
In a further aspect, although this is not shown, a winding roll lifting device may include a winding roll holding device 40, wherein the holding device 40 includes a chuck member 8a. The chuck member 8a includes a shaft member 38 mounted to the forward end of the chuck member 8a so that the shaft member 38 can advance or retract in the axial direction of the chuck member, and an eccentric cam member 39 is pivotally supported on the forward end of the chuck member 8a and operatively linked with the advancing or retracting movement of the shaft member 38 so that the eccentric cam member 39 can turn pivotally in the axial direction of the chuck member 8a. 
According to the aspects of the present invention as described above, the distance between the vertical line position of that part of the lifting device 1 that dynamically acts as the force point (which corresponds to the location of the hook member in the lifting device) and the vertical line position where the center of gravity of the winding roll can be kept as small as possible, when any massive, elongated winding roll is being lifted from its vertical position into its horizontal position. Thus, the movement of such winding roll from the vertical position into horizontal position can occur with high safety and with high speed.
When the holding device 40 is used with the lifting device, it may ensure that the movement of the winding roll being lifted by the chuck member can proceed with safety, without causing the winding roll to slip out of the chuck member.